Lucius Alexander Plantagenet Cary is the first son and heir of Lucius Cary, the 15th Viscount Falkland, by his first wife Caroline Anne Butler. As heir to Viscount Falkland he has the courtesy title of Master of Falkland. The Master uses Alexander as first name.
Alexander is married to American actress Jennifer Marsala. They were wed in Somerset, England on December 31, 2013. He has two sons from previous relationships, Lucius and Sebastian.
Alexander is a former officer of the 2nd Battalion Scots Guards.
Alexander Cary co-wrote and produced the thriller Sacred Cargo. He is a television writer, having written for and/or produced The Riches, Homeland, Lie to Me, and In Plain Sight. He has pilot TV projects both in England and the U.S.